Range finder



Feb. 13, 1940. D. A. SEALEY RANGE FINDER,

Filed April 25, 1938" INVENTOR Ja /0 6. 6.4;- 445! ATTORN EYS Patented Feb. 13, 1940 UN T- T STATES" PATENT OFFICE auam man man David'A.8ealey,EaltOl-ange,l-l.'J."'

Application April 25, 19:3. Serial u some d 5 Claim. (01. 3344' i I *Thisinventionjr'elates toimpro've'ments inrangefinders and h s for one of itsobjects the provisio'n of a device of simple, practical and econom- I ical construction by; means of which distances;

5 within theran e of the instrument may be, at least, approximately determined. 7 Another object is to mount a diaphragm in-as- .sociation with an elongated tube provided with a sightopening at one end thereof, and to provide l iorthe adjustment'ot said-diaphragm'relative to said opening to pdsitions wherein the visual an: vgle between said opening and diaphragm, with respect toa distant object, may be obtained,iand

' I 'the distances to-said' object-determined by the 1 position of said diaphragm relative to calibrated graduations on said tube. The above and other objects will appearmore clearly from the following detailed description whentaken in connection with the accompanying of the inventive idea.

i2 0 drawing which illustrates preferred embodiments In thedrawing:

' Figure 1 is a side elevationof-a range finding" instrument constructed in accordance; with one:

25 form ofthe invention.

Figure 2 15 a longitudinal section'therethrough."

' Figure'3 is 'a section onthe line, 3-4 ot'Fig.,2. I

Figure 4 is a view similar to Fig. zrshowing another form of-the-inventionf- 30 Figure 5 is a'transverse section through the-deg viceoiFigd.

Among the practical uses to'which an instrument of the characterherein-described maybe adapted; is one in'which a golfer desires to as-' 35 certain the approximate distanceto a given point such as the pin orotherobjecton a golf green.

By sighting the instrument on said object which,

Referring more particularly to Figs. 1 to 3 the 50. instrument is shown as'compri sing an elongated tube It of uniform diameter having'one end I l thereof closed and provided therein with a pinholesized sight opening l2; Ii desired, an-eyepiece in the form of an opene'nded sleeve I3 55 may-be slidably mounted upon the closed endof eter.

the'tube "by a pin and slot connection 14, this eye-piece being provided for the purpose oi spa'ce.

ing the eye'of the observer from the sight opening I 2 whenusing the instrument. Between the ends oi'thetube the same is provided with an' 5 elongated longitudinally extending slot 15 the lengthof which is determined'by the size of the instrument" and" the eflective range thereof, the inner and outer ends oi the slot'representing, re a spectively, the minimum and maximum distances 10 which-may be ascertained by the use of the instrument; Along one edge of the opening the tube. has markedlthereon the distance graduations l6 which-are calibrated in accordance with certain V iacto'rs including the known height of the distantobject. upon which the instrument is focused,

the length of the slot 15 and the distance of any v,extreme or-mean point thereof from thesight opening l2, and the eflective size of the center of the diaphragm l1, which is slidably mounted withinthe tube ID for adjustment-toward and away from the sight opening l2. As disclosed in the modification being described, the diaphragm II is in the form of a disc 01 a diameter which ffits within the tube Hi and is provided with a dentral opening iaaligned'with thesight opening I 2 and of larger size-than the latter opening d e-t pending upon the range of the instrument as, forexample, about one sixteenth of an inch in diam- A reduced webl9 of the diaphragm I1 projects through the slot l5 in'the tube It and terminates exterioriyoi said tube in a circumferentially extending recessed flange 20.,which contacts the ex terior of said tube so as to actas a guide for the.

diaphragm as the latter is adjusted along the length of the tube. A small leaf spring 2| may be seated within the recess of the flange 20 with its ends engaging the exterior of the tube so as to exert an outwardpressure upon the flangeztl and 40 thus maintain the lower portion ofthe periphery of the diaphragm I! in intimate frictional contact with the interior of the tube It) so that the diaphragm will be held in various positions of adjustment along the tube. In order to manipulate the diaphragm, the flange?!) is provided with an extension .22 forming a handle or finger piece which may be" gripped when sliding the diaphragm back and forth. The flange is also pro- 'vided. with a pointer 23 which moves along'the graduations "l6 whenthe diaphragm is adjusted and which is utilized to indicate the distance from the "observer to a distant object after the diaphragm has been properly focused'upon the latter so that the top and bottom of the opening it are aligned with the upper and lower extremities of said distant object, thereby ascertaining the visual angle indicated by the dot and dash lines 24. When the visual angle has thus been ascertained by the adjustment of the diaphragm longitudinally of the tube the pointer 23 will then indicate on the scale or graduation it the distance from the sight opening i2 to the distant object. Such distance is in the same proportion to the height of the object as the distance between the openings I2'and i8 is to the diameter of the latter opening. Thus, there is present the equation wherein DzO: :dzo, in which large D is the unknown distance, large the known height of the distant object, small (1 the known distance between the openings 12 and i8, and small 0 the known diameter of the opening l8.

In the embodiment of the invention shown in Figs, 4 and 5 the diaphragm 25 is in the form of a ring fitted within the tube l0 and having supported in its center an object such as a small ball 26 which may boot the same diameter as the opening I8-in the diaphragm l'l. Said ball may be mounted in position by means of two diametrically extending wires 21 having their outer ends secured to the inner periphery of the ring 25 and their inner-ends to opposite sides of the ball 26. Otherwise the diaphragm and its associated parts such as the flange 20 and handle 22 are of the same construction as shown in Fig. 3. Likewise, the diaphragm is adjustable back and forth within the tube l0, when sighting a distant object, until the ball 26 is in a position wherein the same will obscure from the vision of the observer the two vertical extremes of the distant object, thereby ascertaining the visual angle and the resultant distance on the scale It.

What is claimed is: v

1. In a range finder, a tube having a sight opening therein and provided with a longitudinal slot, distance graduations along one edge of said slot, a diaphragm within said tube and having an aperture therein of greater diameter than said sight opening and alined therewith, and means including a pointer carried by said diaphragm and extending through said slot for adjusting said diaphragm longitudinally of said tube to ascertain the visual angle between said sight opening and a distant object through said aperaiaacee ture, said pointer moving over said graduations.

2. In a range finder, a tube having a sight opening therein and provided with a longitudinal slot, distance graduations along one edge of said slot,

a diaphragm within said tube and having an aperture therein of greater diameter than said sight opening and alined therewith, means including a pointer carried .by said diaphragm and extending through said slot for adjusting said diaphragm longitudinally of said tube to ascertain the visual angle between said sight opening and a distant object through said aperture, said pointer moving over said graduations, and a spring interposed between said tube and said diaphragm adjusting means.

3. In a range finder, a tube having a sight opening therein, a sighting diaphragm movable longitudinally'within said tube and relative to said sight opening, and cooperating indicating means on said tube and diaphragm for ascertaining the distancepf a distant object from said sight opening as said diaphragm is moved relative to saidtube to vary the visual angle between said object and opening through said diaphragm.

4. In a range finder, a tube having a sight opening therein, and further having a slot extending longitudinally thereof, distance graduations on said tube adjacent said slot, a sighting diaphragm within said tube cooperating with said sight opening, and means carried by said diaphragm and extending through said slot or adjusting said diaphragm along said tube to secure the distance between the former and said sight opening, said means having a pointer in association with said graduations.

5. In a range finder, a tube having a sight opening therein and provided with a longitudinal slot, distance graduations along one edge of said slot, a diaphragm movable along said tube and supporting an object-obscuring member in alignment with said opening, said diaphragm being movable along said tube to positions wherein said member will obscure a distant object and thereby determine the visual angle between said opening and said object, and a handle for said diaphragm extending through said slot and havin a pointer cooperating with said graduations.

DAVE) A. SEALEY. 

